A high system voltage usually means the battery is being overcharged, which can damage it and the car's electronics, so arrange a charging system check soon.
Trouble codes · P0563
P0563 meaning
System Voltage High
The same first verdict Car Assist shows from this code alone, before a diagnosis. The code does not tell the app whether the warning light is flashing.
What this code doesn’t tell you
A code says where the car noticed a problem. It does not prove which part failed, whether the fault is still present, or what repair this car needs. The engine, other codes, freeze frame and live readings matter.
Usual causes, most likely first
The order is a starting point across cars; the exact engine and its readings can change it.
- Alternator voltage regulator fault
- Poor battery sensor or ground connection
- Incorrect battery or charger connected
What you can check
Note flickering or very bright lights, a hot battery or a sulphur smell. Usually a swollen, hot or smelly battery needs the engine switched off and a check before driving on. Have the charging system tested soon.
Words the car uses
- Stored codes
- Faults the car has confirmed and saved. They help explain a check-engine light, but a code alone does not prove which part needs replacing.
- Freeze frame
- A snapshot of the engine's readings when a fault was recorded. It helps show the conditions that caused the fault, even if the car now seems fine.
- Readiness monitors
- The car's own checks of its emissions systems. An unfinished check means the car has not tested that system yet, so a clean code scan may miss a fault.
- Battery and ECU volts
- The electrical supply measured at the adapter or a car computer (ECU). Low readings can explain starting problems or unreliable diagnostic connections.
Find out what’s causing yours
Car Assist reads your car through an OBD-II adapter and your iPhone. Its assistant uses the codes, freeze frame and live readings to work through the likely cause with you.